Lens surfacing machine



LENS SURFACING MACHINE Filed Sept. 18, 1957 2 Sheets-Sheet 1 INVENTOR. GEORGE C.SCHELLI NG ATTORNEYS April 1959 I G. c. SCHELLING 2,880,556

LENS SURFACING MACHINE Filed Sp'b. 18, 1957 2 Sheets-Sheet 2 INVENTOR. GEORGEG SCHELLI NG v .4 Sim ATTORNEYS United States Patent LENS SURFACING MACHINE George C. Schelling, Irondequoit, N .Y., assignor to Bausch & Lomb Optical Company, Rochester, N.Y., a corporation of New York Application September 18, 1957, Serial No. 684,758

' 3 Claims. (Cl. 51-124) This invention relates to lens surfacing machines and more particularly it relates-to mechanism by which the stroke length is changed in certain lens surfacing movements that are used in forming the lens.

It is the principal object of this invention to provide improved mechanism for changing the length of stroke of the lens surfacing movements which will be smooth and reliable in action, simple and sturdy in construction as well as easy to assemble, operate and service.

Further objects'andadvantages will be found in the form, arrangement'and combination of parts and in the details of construction found therein by reference to the specification herebelow and the accompanying drawings wherein:

Fig. l is a general perspective view of a lens surfacing machine'embodying my invention,

I Fig. 2 'is a substantially midsectional view of one form ofrny invention, certain parts thereof being broken away and fragmentarily shown for purposes of illustration,

I Fig.3 is a cross-sectional view taken on the line 3 -3 of Fig. 2 of certain parts of my invention shown in one operative position,

Fig. 4 is a cross-sectional view similar to Fig. 3 showing the same parts in a second operative position,

Fig. 5 is a cross-sectional view taken on the line 5--5 of Fig. 2, and

Fig. 6 is a front elevation of the lens holding parts and the lens surfacing tool shown in one operative position.

With reference to Fig. l of the drawings, there is illustrated a lens surfacing machine 10 wherein my invention is embodied, said machine having a casing 11 from which projects on the operators side a pair of work arms or spindles 12 and 13. In a manner well known in the are, each of the spindles is adapted to move a lens blank 14 with complex surfacing motions back and forth across a revolving surfacing tool 15 as shown in Fig. 6. The spindles 12 and 13 are actuated by an interior oscillating mechanism, a part of which is shown fragmentarily at 16, from a motor shaft 17, Fig. 2, through a stroke changing mechanism generally designated by numeral 18, and through a motion break-up device, generally designated by the numeral 19, which is drivingly connected in tandem thereto. A swivel joint 21 is provided for connecting the part 16 of said oscillating mechanism to said motion break-up device 19.

Said stroke changing mechanism 18 is constructed upon a rotatable hollow drive sleeve or quill 22 which is rotatably mounted on spaced ball bearings 23 and 24 which are fitted at its opposite ends. These bearings are preferably held in opposite ends of a casing extension 25 which is attached by the screws 26 to the casing 11 whereby the sleeve is rotatably supported by an outboard bearing exteriorly of the casing. Adjacent to the inner end of the sleeve 22, a pulley 27 is non-rotatably keyed thereon as shown at 28 and said pulley is connected by a flexible belt 29 to a drive pulley 31 which is suitably fixed to the drive shaft 17.

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On the inner end of the drive sleeve 22 is formed an eccentric flange 32 whereto a cylindrical shell 33 is fixed by means of several bolts extending therethrough, one of which is shown at 34. Within the shell 33, there is formed a cylindrical bore 35 having its axis offset laterally of the axis of the drive sleeve 22. Rotata-bly seated in said bore 35 is a cylindrical shaft head 36 from which extends an axially offset integral shaft 37 whereby power is transmitted from the stroke changing mechanism 18 to the motion break-up device 19. To retain the cylindrical head 36 in the bore 35, an inwardly directed annular lip 38 is formed on the inner end of the shell 33.

According to this invention, gearing means are provided for rotating the head 36 within the shell 33 so as to change the length of stroke of said mechanism 18 comprising a shaft 40 which is rotatably fitted within a concentric bore in the drive sleeve 22 and projects at its inner end into said cylindrical shell. On said inner end of shaft 40, a pinion 41 is fixed in any suitable manner, such as by pressing or brazing. The rotatable head 36 is provided on the side adjacent to said pinion 41 with an annular rim 42 having an inner cylindrical portion whereon an internal gear 43 is formed in position to mesh with the pinion 41 so that rotation of shaft 40 causes rotation of the head.

One extreme angular operative position of the head 36 is shown in Fig. 4 .wherein its integrally extending shaft 37 is shown by a dotted circle. The center 44 of said shaft 37 is there shown as being separated by a distance a from the center of rotation 45 of the shaft 40 and of the shell 33. The distance a may be called the crank arm of the stroke changing mechanism and its length may be varied continuously between minimum and maximum lengths by rotation of the shaft 40. In Fig. 3, the opposite extreme angular position of the head 36 is shown wherein the shaft 37 is shown -by a dotted circle which is concentric with the shaft 40 since in this instance the shaft 37 is eccentric with respect to the head 36 by a distance The shaft 40 is rotated from outside of the machine 10 by a knob 46 which is slidably mounted thereon and is keyed for rotation therewith by an axial pin 47 which is anchored at one end in the knob and has a sliding engagement with an opening in a disk 48 at the other end. Said disk 48 is anchored to shaft 40 by a crosspin 49 extending through aligned and fitted openings in both members. On the outer end of the drive sleeve 22 a drive plate 50 is suitably anchored adjacent to the knob 46 and mating teeth 51 and 52 are formed on the abutting parts of the knob and plate, respectively, whereby a disengageable clutch connection is effected and the mating teeth are normally held in engagement by one or more compres sion springs 53 seated in opposite blind holes 54 and 55 formed in the knob and plate, respectively.

Since only of rotation of the head 36 relative to the shell 33 is required to produce the maximum axial separation a, as shown in Fig. 5, stop means are provided limiting said rotation to that extent consisting preferably of an abutment lug or screw 56 which is threaded in an opening through the shell so as to project into a free fitting groove 57 formed in the head, and consisting further of two circumferentially spaced abutment elements such as the pins 58 and 59 which are fixed in said head in abutting relation to said screw at opposite ends of its travel.

When it is desired to change the length of stroke of the base curve or cross curve movement of the lens holding arms 13 and 14, the machine 10 is stopped, the knob 46 is pulled outwardly to disengage the clutch teeth 51 and 52. The knob is then rotated to the desired setting on scaIe; 61 and, released tov reengage the clutch. When the knob 46 rotates the shaft 40 and pinion t1, the internal gear 43 and consequently the shaft head 36 is rotated in the shell 33, thus carrying the axis of the shaft 37 in an are 60, Fig. 3, having a diameter equal to the maximum value of the crank arm a. Any crank arm or throw less than maximum such as shown at a, Fig; 3, terminates as shown on the arc 60 as the mechanism is adfasted for shorter strokes.

Although but a single form of my invention has been shown and described in detail, it will be understood that an effective stroke changing mechanism has been provided in fulfullment of the objects of my invention, and changes and substitutions may be made in the precise form shown without departing from the spirit of the invention as claimed below.

I claim:

I. In a lens surfacing machine, the combination comprising a lens surfacing mechanism for producing oscillatory lens surfacing movement, a casing for covering the same, a rotatably mounted drive sleeve and a shaft rotatably journaled therein and projecting through an opening in the casing, a cylindrical shell formed on the inner end of said sleeve and having a bore therein with its axis eccentric and parallel to the sleeve and further comprising a driven shaft extending away from the sleeve from a point adjacent to the inner end of the first shaft and parallel thereto, said driven shaft having a head portion fixed thereon which is journaled in the bore of said shell, an annular flange formed peripherally on said head portion on the side opposite to said driven shaft,

and gearing means operatively formed on said flange and on the adjacent end of the first said shaft for rotating said head portion within said shell whereby the axial separation between the first and the second-named shafts is changed whenever the first shaft is rotated relative to said sleeve, and means operatively connecting said second shaft to the surfacing mechanism whereby relative rotation between said sleeve and the first shaft causes a change in the length of stroke of the mechanism.

2. In a lens surfacing machine, the combination comprising a lens surfacing mechanism for producing oscillatory lens surfacing movement, a casing for covering the same, a rotatably mounted drive sleeve and a shaft rotatably journaled therein and projecting through an open- 4 ing in the casing, a cylindrical shell formed on the inner end of said sleeve and having a bore therein with its eccentric andv parallel to the sleeve and comprising a driven shaft extending away from the sleeve starting in the proximity of the inner end of the first shaft and parallel thereto, said driven shaft having a head portion fixed thereon which is journaled on the surface of said bore, an annular flange formed peripherally on said head portion oppositely to said driven shaft, gearing means operatively formed on said, flange and on the adjacent end of the first said shaft for rotating, said, head portion within said shell, and rotational stop means for said head portion including an abutment lug located. between. two circumferentially spaced abutment surfaces, said lug and surfaces being located in cooperative relationship to each other on said shell and said head portion whereby the axial separation between the first and the secondnamed shafts is changed whenever the first shaft is rotated relative to said sleeve.

3. In a lens surfacing machine, the combination comprising a lens surfacing mechanism for producing oscillatory lens surfacing movement, a casing for covering the same, a rotatably mounted drive sleeve and a shaft rotatably journaled therein, said shaft and sleeve extending outwardly through said casing, disengageable clutch means formed on the respective outer ends of said sleeve and shaft for changing the relative angular relation be tween the members, a cylindrical shell fixed co-extensively to the inner end of said sleeve and having a bore locatedtherein eccentrically and parallel to said sleeve, a head member having a cylindrical surface thereon which is rotatably fitted within said bore and having a cylindrical recess thereon on one side concentric with said surface, a second shaft projecting from said head member parallel to said sleeve on the side opposite to said recess and located eccentrically of said cylindrical surface, an internal gear formed on the cylindrical part of said recess in said member, a pinion fixed to the inner end of the first said shaft in meshing relation with said internal gear, and means operatively connecting said second shaft to said mechanism whereby relative rotation between said sleeve and the first shaft causes a change in the length of stroke of said mechanism.

Thompson Mar. 14, 1899 Goddu Feb. 28, 1933' 

